Field of the Invention
The present invention generally relates to a transmission for a hybrid vehicle. More particularly, the present invention relates to the structure of a power split parallel-type hybrid transmission.
Description of Related Art
Power split parallel-type hybrid transmissions can be designed to divide power generated by an engine into a mechanical power flow based on planetary gears and an electric power flow based on a motor, a generator, and a battery. It is possible to operate the engine independently of an output shaft, freely turn on or off the engine during traveling, and enable an electric vehicle mode. In addition, it is possible to efficiently operate the engine due to the effect of an electrically variable transmission (EVT) enabled by two motor generators without any power-disconnecting mechanism.
It is preferable that a transmission for a hybrid vehicle obtain a sufficient amount of drive force while using a smaller motor by obtaining a sufficient reduction gear ratio. This can consequently reduce the weight of a vehicle and increase the energy efficiency of the vehicle, thereby improving the fuel efficiency of the vehicle, such that the appropriate and efficient high-speed driving performance of the vehicle can be obtained.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.